## Audio policy configuration for generic device builds (goldfish audio HAL - emulator)#这是模拟器的Audio policy配置## Global configuration section: lists input and output devices always present on the device# as well as the output device selected by default.# Devices are designated by a string that corresponds to the enum in audio.h#全局配置部分：列出了设备上总是存在的输入输出设备，它也是系统默认选择的输出设备#这里的输入输出设备必须是audio.h中列出的枚举类型global_configuration {  attached_output_devices AUDIO_DEVICE_OUT_SPEAKER  default_output_device AUDIO_DEVICE_OUT_SPEAKER  attached_input_devices AUDIO_DEVICE_IN_BUILTIN_MIC|AUDIO_DEVICE_IN_REMOTE_SUBMIX}# audio hardware module section: contains descriptors for all audio hw modules present on the# device. Each hw module node is named after the corresponding hw module library base name.# For instance, "primary" corresponds to audio.primary.<device>.so.# The "primary" module is mandatory and must include at least one output with# AUDIO_OUTPUT_FLAG_PRIMARY flag.# Each module descriptor contains one or more output profile descriptors and zero or more# input profile descriptors. Each profile lists all the parameters supported by a given output# or input stream category.# The "channel_masks", "formats", "devices" and "flags" are specified using strings corresponding# to enums in audio.h and audio_policy.h. They are concatenated by use of "|" without space or "\n".#audio hardware module部分：包含了对设备上的所有的audio hw modules的descriptors，每一个hw module节点#的名字都与相应的so库名称相对应，例如："primary"对应audio.primary.<device>.so。其中"primary"module是#必须的，而且它必须包含一个含AUDIO_OUTPUT_FLAG_PRIMARY标志的output，每一个module的descriptor必须至少#包含一个output配置descriptor和大于等于0个的input配置descriptor，每一个配置都描述了输入输出流类型支持#的参数，其中的 "channel_masks"、"formats"、"devices"和"flags"必须为audio.h、audio_policy.h中定义的枚#举值，它们可以通过|连接，但不能包含空格和"\n"。audio_hw_modules {  primary {    outputs {      primary {        sampling_rates 44100        channel_masks AUDIO_CHANNEL_OUT_STEREO        formats AUDIO_FORMAT_PCM_16_BIT        devices AUDIO_DEVICE_OUT_SPEAKER        flags AUDIO_OUTPUT_FLAG_PRIMARY      }    }    inputs {      primary {        sampling_rates 8000|16000        channel_masks AUDIO_CHANNEL_IN_MONO        formats AUDIO_FORMAT_PCM_16_BIT        devices AUDIO_DEVICE_IN_BUILTIN_MIC      }    }  }  r_submix {    outputs {      submix {        sampling_rates 48000        channel_masks AUDIO_CHANNEL_OUT_STEREO        formats AUDIO_FORMAT_PCM_16_BIT        devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX      }    }    inputs {      submix {        sampling_rates 48000        channel_masks AUDIO_CHANNEL_IN_STEREO        formats AUDIO_FORMAT_PCM_16_BIT        devices AUDIO_DEVICE_IN_REMOTE_SUBMIX      }    }  }}